Faculty Publications
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Item Thermodynamic simulation of ammonia-water absorption refrigeration system(Serbian Society of Heat Transfer Engineers, 2008) Sathyabhama, A.; Ashok Babu, T.P.The ammonia-water absorption refrigeration system is attracting increasing research interests, since the system can be powered by waste thermal energy, thus reducing demand on electricity supply. The development of this technology demands reliable and effective system simulations. In this work, a thermodynamic simulation of the cycle is carried out to investigate the effects of different operating variables on the performance of the cycle. A computer program in C language is written for the performance analysis of the cycle.Item Tuned liquid dampers for multi-storey structure: numerical simulation using a partitioned FSI algorithm and experimental validation(Springer India sanjiv.goswami@springer.co.in, 2017) Eswaran, M.; Sathyanath, S.; Niraj, P.; Reddy, G.R.; Ramesh, M.R.Wind-induced and earthquake-induced vibrations of structures such as super-tall towers and bridges can be efficaciously controlled by tuned liquid dampers (TLDs). This work presents a numerical simulation procedure to study the performance of TLDs–structure system through sigma (?)-transformation-based fluid–structure coupled solver. For this, a ‘C’-based computational code has been developed. The structural equations, which are coupled with the fluid equations in order to achieve the transfer of sloshing forces to structure for damping, are solved by the fourth-order Runge–Kutta method, while the fluid equations are solved using finite-difference-based sigma-transformed algorithm. Different iterative and error schemes are used to optimize the code for larger convergence rate and higher accuracy. For validation, a few experiments are conducted with a three-storey structure using TLDs arrangement. The present numerical results of response of TLD-installed structures match well with the experimental results. The minimum displacement of structure is observed when the resonance condition of the coupled system is achieved through proper tuning of TLDs. Since real-time excitations are random in nature, the performance study of TLDs under random excitation has also been carried out in which the Bretschneider spectrum is used to generate the random input wave. © 2017, Indian Academy of Sciences.Item Thermodynamic analysis of window air conditioner using sustainable refrigerant R290/RE170 and R1270/RE170 blends as substitutes to refrigerant R22(International Information and Engineering Technology Association info@iieta.org, 2019) Vali, S.V.; Setty, A.B.T.P.The present work emphasis on theoretical computation of thermodynamic performance of window air conditioner using various sustainable R290/RE170 and R1270/RE170 refrigerant mixtures as substitutes to R22. In this work, apart from R407C, twelve new binary mixtures comprising of R290, R1270 and RE170 at various compositions were developed. And also in this investigation, a MATLAB code was developed to compute the thermodynamic performance characteristics of various considered R22 alternatives at Tk=54.4 0C and Te=7.2 °C. The various performance characteristics computed are mass flow rate, refrigeration effect, compressor work, coefficient of performance (COP), pressure ratio, compressor discharge temperature, power consumed per ton of refrigeration, condenser heat rejection and volumetric cooling capacity. Results showed that the COP of refrigerant mixture RM7 (R1270/RE170 95/5 by mass %) was the highest among twelve refrigerants studied and it was 0.23 % higher than R22. Pressure ratio of RM7 (3.174) was 7.49 % lower than that of R22 (3.431). Compressor discharge temperature of all the twelve investigated refrigerants was lower in the range of 9.35 0C to 17.15 0C when compared with R22. Power consumed per ton of refrigeration of RM7 was 0.27 % lower than that of R22. Volumetric cooling capacity of RM7 (3833 kJ/m3) was very close to that of R22 volumetric capacity (3863 kJ/m3). Heat transfer through condenser of RM7 (6.372 kW) was similar to that of R22 (6.377 kW). Overall, thermodynamic performance of RM7 matches well with the performance of base line refrigerant R22 and hence, refrigerant RM7 can be considered as sustainable alternative to R22 used in air conditioners. © 2019 International Information and Engineering Technology Association. All rights reserved.Item An overview of the shared task on machine translation in Indian languages (MTIL)-2017(De Gruyter peter.golla@degruyter.com, 2019) Anand Kumar, M.A.; Premjith, B.; Singh, S.; Rajendran, S.; Padannayil, K.P.In recent years, the multilingual content over the internet has grown exponentially together with the evolution of the internet. The usage of multilingual content is excluded from the regional language users because of the language barrier. So, machine translation between languages is the only possible solution to make these contents available for regional language users. Machine translation is the process of translating a text from one language to another. The machine translation system has been investigated well already in English and other European languages. However, it is still a nascent stage for Indian languages. This paper presents an overview of the Machine Translation in Indian Languages shared task conducted on September 7-8, 2017, at Amrita Vishwa Vidyapeetham, Coimbatore, India. This machine translation shared task in Indian languages is mainly focused on the development of English-Tamil, English-Hindi, English-Malayalam and English-Punjabi language pairs. This shared task aims at the following objectives: (a) to examine the state-of-the-art machine translation systems when translating from English to Indian languages; (b) to investigate the challenges faced in translating between English to Indian languages; (c) to create an open-source parallel corpus for Indian languages, which is lacking. Evaluating machine translation output is another challenging task especially for Indian languages. In this shared task, we have evaluated the participant's outputs with the help of human annotators. As far as we know, this is the first shared task which depends completely on the human evaluation. © 2019 Walter de Gruyter GmbH, Berlin/Boston.Item Commutators close to the identity in unital C*-algebras(Springer, 2022) Mahesh Krishna, K.M.; Johnson, P.S.Let H be an infinite dimensional Hilbert space and B(H) be the C∗-algebra of all bounded linear operators on H, equipped with the operator-norm. By improving the Brown–Pearcy construction, Tao (J. Oper. Theory82(2) (2019) 369–382) extended the result of Popa (On commutators in properly infinite W∗-algebras, in: Invariant subspaces and other topics (1982) (Boston, Mass.: Birkhäuser, Basel)) which reads as: for each 0 < ε≤ 1 / 2 , there exist D, X∈ B(H) with ‖ [D, X] - 1 B(H)‖ ≤ ε such that ‖D‖‖X‖=O(log51ε), where [D, X] : = DX- XD. In this paper, we show that Tao’s result still holds for certain class of unital C*-algebras which include B(H) as well as the Cuntz algebra O2. © 2022, Indian Academy of Sciences.Item Nanoscale Tapered Hybrid Plasmonic Waveguide for On-Chip Silicon Photonics(Springer Science and Business Media B.V., 2022) Reddy, S.K.; Singh, M.Plasmonic waveguides which deploy surface plasmon-polariton (SPP) waves are of colossal interest to the researchers with their ability to realize and integrate nanophotonic circuits beyond the diffraction limit. In order to subjugate the demerits of plasmonic and dielectric waveguides, the light guided by plasmonic and dielectric waveguides are coupled to form hybrid plasmonic waveguide (HPWG). In this work, we have simulated a nanoscale tapered plasmonic waveguide (Au-SiO2-Si) using COMSOL Multiphysics software in the telecommunication C-band. The proposed waveguide shows better normalized effective mode area (Aeff/A= 0.056), enhanced electric field confinement, and long propagation length (Lp = 101.55 μm) with h= 350 nm, WAu = 100 nm, WSlot=20 nm, WSi = 220 nm, and ht=150 nm. The finite element method based approach shows that this enounced waveguide is a feasible choice for the future on-chip nanophotonic devices. © 2021, Springer Nature B.V.Item Adaptive-Energy-Sharing-Based Energy Management Strategy of Hybrid Sources in Electric Vehicles(MDPI, 2023) Sidharthan, V.P.; Kashyap, Y.; Kosmopoulos, P.The energy utilization of the transportation industry is increasing tremendously. The battery is one of the primary energy sources for a green and clean mode of transportation, but variations in driving profiles (NYCC, Artemis Urban, WLTP class-1) and higher C-rates affect the battery performance and lifespan of battery electric vehicles (BEVs). Hence, as a singular power source, batteries have difficulty in tackling these issues in BEVs, highlighting the significance of hybrid-source electric vehicles (HSEVs). The supercapacitor (SC) and photovoltaic panels (PVs) are the auxiliary power sources coupled with the battery in the proposed hybrid electric three-wheeler (3W). However, energy management strategies (EMS) are critical to ensure optimal and safe power allocation in HSEVs. A novel adaptive Intelligent Hybrid Source Energy Management Strategy (IHSEMS) is proposed to perform energy management in hybrid sources. The IHSEMS optimizes the power sources using an absolute energy-sharing algorithm to meet the required motor power demand using the fuzzy logic controller. Techno-economic assessment wass conducted to analyze the effectiveness of the IHSEMS. Based on the comprehensive discussion, the proposed strategy reduces peak battery power by 50.20% compared to BEVs. It also reduces the battery capacity loss by 48.1%, 44%, and 24%, and reduces total operation cost by 60%, 43.9%, and 23.68% compared with standard BEVs, state machine control (SMC), and frequency decoupling strategy (FDS), respectively. © 2023 by the authors.Item Bat Optimization Model for Electric Vehicle Route Optimization Under Time-of-Use Electricity Pricing(Springer, 2023) Vani, B.; Kishan, D.; Ahmad, M.W.; Naresh Kumar Reddy, B.In the framework of fuel reduction and energy conservation, the electric vehicles (EV’s) has been identified as a promising option in contrast to fuel-driven vehicles. EV’s battery limits to require visiting a greater number of times to the recharging stations, which must be viewed as in the route planning to keep away from inefficient vehicle routes with lengthy diversions. These problems have to consider, we propose an Efficient Electric Vehicle Route Optimization with Time-of-Use Electricity Pricing using Bat algorithm. Which can reduce the used vehicles as well as electricity-cost and total travel distance. Additionally, functional model and collective models are used to minimize the objectives: distance and cost. The computational assessment in light of the notable benchmarking test instances exhibits, proposed optimization algorithm electricity cost conservation on average 12.17% with Learnable Partheno-Genetic Algorithm (Yang et al. in IEEE Trans Smart Grid 6:657–666, 2015) 8.45% with VNS/TS Algorithm (Lin et al. in Trans Res Part-C 130:103285, 2021) and 5.15% with Mixed Integer Programming model (Ham and Park in IEEE Access 9:37220–37228, 2021). © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.